Method of making patterned rubber sheeting



July 5,1927. 1,634,955

T. J. MELL.

METHOD OF MAKING PATTERNED RUBBER SHEETING Filed NOV. 24, 1924 l, HWY/f 143/1/4 6 15 Hlllllllll l5 f4 fl 14 20 v19 `15 'ron a. tanta, or Annen, omo,l Assrenon ro THE n. r. eoennreir COMPANY, ornnw Yoan, n. Y., A conrozaa'rron or naw Yoan.

METHOD OF MAKING' PATTERNED RUBBER, SHEETING;

Application led November 24, 1924. Serial No. 751,878.

This invention relates to the manufacturel ment upon that of my United States Patent No. 1,5s8,797,g1anteaJune 15,1926. It has to obtain a single-thickness product, but sotill) interstices, and iowing unvulcanized stock preferably so formed, as shown, that the 'in- Fille p for its chief object the provision of improved procedure and apparatus whereby sheets of which the designscomprise narrow inlaid or interposed elements maybe conveniently and economically made. A further object is to provide van improved mold having elements adapted to be readily substituted or rearranged to produce sheets'having different patternsor designs, l

I am aware that in the production of linoleum of tesselated pattern and in the tile industry, for example, it has `been proposed to produce a patterned assembly by arranging tesserae in spaced relation, or forming a mass of material with raised figures thereon, and filling the intervening spaces with appropriate material by .sprinkling it in granular form or flowing it inplastic form, and consolidating the mass,

far as I am awareV such procedure heretofore has never been employed, either by itself or in combination with other features of my invention, in the production of soft rubber sheets. It is of course desirable in' producing patterned rubber sheets that thepattern bev defined or delineated vby accurate lines of demarkation between the elements of 'different colors, and in my copending application above identified I have accomplished this result by separately forming the interfitting elements; as by molding both or all of them prior to their presentation to each other.

Although rubber is not Well adapted to be used in granular form as proposed with reference to linoleuin in the procedure above described, or to be accurately filled into interstices between soft rubber elements by propelling a mass of it ahead of a scraper, as has been proposed for filling a cement matrix with ltiling cement, 1 now find that the dcsired clearness of outline or delineation of the design in a soft rubber sheet may be obs tained by employing a rubber matrix, preferably partiall vulcanized, with raised elements having t ieir upper faces substantially flush with each other and separated by open of another color into the interstices, preferably by applying to the said upper faces of the elements anV unvulcanized rubber sheet of approximatelyv uniform thickness and pressing it thereon uniformly throughout an ext-ended area, so that pressure of the unvulcanized stock against the raised elements of the matrix is chiefly normal. thereto and, substantially uniform throughout, in order that the flow of the unvulcanized rubber into the interstices shall not-so distort the said elements as to destroyv ther accuracy of the design. I I

I also lind that by cutting the resulting mass through lines of color division therein, 1n a plane passing through the above mentioned4 raised elements of the matrix, especially accurate and definite color demarkation may be obtained. i

The rubber composition which is to represent the greater area in the design'is preferably used for the matrix, in order that the raised elements thereof ,may be of sufficient extent to resist distortion as the 'other rubber composition is pressed into the interstices.

1 My preferred procedure and apparatus are illustrated in the accompanying drawings, of

' which:

Fig. 1 is a perspective view,'with a part broken away, of mold apparatus embodying and adapted to carry out myinvention in its preferred form, at an early stage of'tlie process, and a rubber matrixr therein.

Fig. 2 is a fragmentary section of preferred molding apparatus and the work therein at a later stage.

Fig.A 3 is a perspective view. of a piece of the work produced in accordance with my invention, in the process of being split by vpreferred apparatus there shown.

Fig. 4 is a fragmentary, perspective view of a mold including preferred means, adapted to be readily substituted or rearranged, for producing matrices of different designs.

The apparatus shown in Fig. 1 of the accompanying drawings comprises a mold 10 formed with a mold cavity 11, a grid 12 adapted to .be pressed into a charge of stock` in said 4mold and, with the mold and permissibly with a suitable cover plate therefor, to form the matrix, 13, with raised elements 14, 14, separated by relatively narrow grooves or 4interstices 15, 15. The grid is` lll lid

terst-ices all communicate with the edge faces of the matrix, to zii-oid entrappiriam of air as plastic steelt is subseipiently caused to liouf uniformly thereinto from a supei'posed sheet.

The rst part of Athe process comprises molding` the matrix 13 in apparatus such as is shown in Fig. l, a reinforcement or backing sheet of rubberized burlap lli preferably being placed in the bottom of the mold and the mold preferably being` heated und pressed between press platens such as those shown at 17, 18 in Fig. 2 so as to partially vulcauize the rubber.

The press is then opened, the grating; 1Q. is removed, the upper face of the matrix, including the interior faces of the grooves l5, is coated with rubber cement, a sheet of nnvulcunized rubbei` ll) of a different color or composition from that of the matrix 13 is laid over the upper face of the matriz; and pressed thereon by elosinT ol' the press7 and the .mold and its contents are further healed so that the rubber of the sheet lil ilou's into and lills the interstices lli and the composite .mass of rubber is unilied by ruleanization, although preferably not completely vulcanized. is the interstices are thus filled air is rent-ed therefrom at the edge laces of the matrix i3.. ln this part of the process a rubberized bui-lap reiiil'oreeuienl: or backing- 20 preferably is laid upon and vulcanized to the outer face of the sheet lil, and a piece of canvas 2l preferably interposed between the ljiurlap and the upper press platen to prevent adhesion of the two. The rubber sheet 19 Apreferably is relatively thin, so that, While it serves to provide material for filling the interstices and to provide an iutegral connection between the masses of material fillingl the sameg it will be sullieiently thin that a relatively thin 'slice may be tairen from that side of the composite mass by a cut so directed through raised portions of the matrix as to provide the desired surface design. rlhe sheet 1Q also is preferably of a comparatively quick if'uleauizing compound, so that in the `lin-al product it will be vulcanized to approximately the same degree as the matrix.

When the matriz; 13 and the .filler sheet if) have been united as described, the composite :neonata band lrnife adapted to slice the rubber as it einerw from the :nip of the rolls, as deseribel und claimed in my aborcddentified eopending application, such rolls bein@l adapted so to restain the rubber at, the cutting edge of the knife as to produce an accurate cut and yet to release it as it passes from said cutting edge so as to avoid bind-- ing; of the deformable and resilient rubberagainst the faces ofthe knife, one of the cut sheets im ferably being thin, so that, by reason of its flexibility, it will press but lightly ap iiast the knife by signing action and thus avoid gripping of the lrniie.

after the mass has thus been split or sliced into :indiif'iduai sheets, the out surface of each sheet preferably is smoothed by furn ther vulcanizing the sheet with said face in contact With a smoothsurfaced pressing; member. The employment of the fabric backing member, secured to the rubber mass before the latter is sliced, has the advantage, in connection With the smoothing operation, that it permits the handling; of the sliced sheet, as in further ruleanization thereof, Without such distortion of the sheet would destroy the accuracy of thel design in the linished product.

rlhe preferred type'of mold, shown in liig. et, for producing successive sheets having; different designs, comprises a mold section E25 haring shallow cupa or die members Stil, 26 secured to its inner face by screws 2i, 2i' mounted in apertures in their bottoms, the sidewalls of the assembly of cups forming a design which may be modified or varied by changing,n the positions of the cups or sub stitutingr cups of different forni.

`While the die members here shown are in the forni of cupe haring substantially closed, bottoms and are formed and arranged so that their side Walls abut each other throughout, ll do not wholly limit my claims to these features, although the closed bottoms are of adi/aritage in covering screw holes in the mold secli titi tion. which are not at the time occupied hy screws. This type of mold may be used for producing a. matrir of the substantial characteristics of the matrix 'll by pressingl onto the assembly of cups a sheet of stock of suliicient thickness to till the cups and preferably to provide a continuous layer of stock overlying the Walls of the cups and integrally connectingl the masses of rubber pressed into the cups. er rubberized burlap backing such as that shown at 1G in Figa 'l may be applied to the outer face of said layer and vulcanized thereto concurrently with the forming of the matrix. 'lvl/hen the matrix is thus formed it is removed from il the mold, inserted, with the raised element-s of its design exposed, in a suitable mold, and thereafter proceeded With as above described. with relation to the matrix f3.

lily intention is susceptible of anniideam through the `two compositions, the said comreagent appa atus described.

I aim:

l. The method of makingpatterned rubber sheeting which comprises forming a matrix of soft-rubber composition, vfilling the interstices of said matrix with a different soft-rubber composition by liowing it thereinto by pressure, and slicing the resulting structure into `aplurality of sheets bycutting it throughout an extended plane passing limitmy claims to the exact procedure or positions being subjected to vulcanization before the slicing operation. y i l 2. The method of lmaking patterned rubber sheets which comprises forming a matrix. of soft-rubber composition, partially vulcanizing the same, filling the interstices of 4said matrix with a different soft-rubber composition by owing it thereintoy by pressure, and-slicing 'the resulting `structure into a plurality of sheets by cutting it through the two compositions throughout an extended area such as to provide a serviceable sheeting unit.

I 3. The method of making patterned rubber Asheeting which comprises forming a matrix of softrubber composition, filling the interstices of said matrix with a dif-y ferent soft-rubber composition by flowing it thereinto by pressure, and slicing the resulting structure into a pluralityl of sheets by cutting it throughout 4an extended plane i passing through the two compositions, the

said method includinga vulcanizing step by which the two compositions are united..

4, The method of `makin patterned rubbersheets which comprises orming a matrix of soft-rubber composition, partiallyl `vulcanizing the same, iilling the interstices of said matrix with a different soft-rubber composition, and slicing the resulting structure into a plurality of sheets by cutting it through the two compositions throughout an extended area such as to provide a serviceable sheeting unitfthe said method .in-

cluding a vulcanizing step by which the two compositions are united. y

5. The method of making patterned rubber sheeting which comprises forming of -a soft-rubber composition a matrix having relatively extensive raised elements of which the 'outer faces are substantially flush with each other,'said' raised elements being separated by relativelynarrow interstices, placing a sheet of another, unvulcanized rubber composition upon the said faces of the sald elements and so pressing it thereon as to cause the said interstices to be lled by flow of stockfrom the said sheet, and slicing the resulting structure into a plurality of s eets by. cutting it through the two compositions throughout an extendedarea such as to provide a serviceable sheetin unit.

6. The method of making patterned rubber sheeting which comprises forming of a soft-rubber composition a matrix having relatively extensive raised elements of which the outer faces are substantially flush with each other, said raised elements being sepa-- rated by relatively narrow interstices, lacing a sheet of another, unvulcanized ru ber composition upon the said faces of thesaid elements and so pressing it thereon as to cause the saidY interstices to be ed by flow of stock from the said' sheet, and slicin the resulting structure intoya plurality of's eets by cuttingl it throughthe two compositions throughout an extended area such 'as topro- Vide a serviceable sheeting unit, the said method including a vulcanizing step by which the two compositions are united.

7 The method of making patterned rubber sheeting which comprises forming of a soft-rubberA composition a matrix having relatively extensive raised elements of which the outer facesare -sulfistantially ush with each other', said raised'elements being separated by relatively. narrow interstices, partially vulcanizing said matrix, placing a sheet of. another, unvulcanize'd rubber composition upon the said faces of the said elements and so pressing it thereon as to cause the said interstices to` be filledNby flow of stock from the said sheet, then uniting -the two compositions by vulcanization, and

thereafter slicing theresulting structure into 8. A method as defined in'claim 4 in which a relatively quick-Vulcanizing compound isv used for lling the matrix.

` 9. A method as dened in claim 3 in which' a backing elementis joined ,to one of the compositions by vulcanization before the slicing operation.'l

10. A method as defined in claim 4 in which the matrix is coated with rubber cei ment before being filled with the second composition.

In witness whereof I have hereunto set my hand this 13th day'of November, 1924.

TOD J. MELL. 

